A host of companies have been scrambling for a leadership position in one of the hottest areas of the economy: providing the technology needed by businesses to embrace the cloud.

You could call them the cloud’s arms merchants.

They’re the ones providing the DNA upon which businesses are building all of their apps and infrastructure and which enables it all to all talk together.

They include big, recognized names like IBM and Microsoft but also smaller, emerging companies like MuleSoft, Rightscale, and New Relic. All of them are helping businesses transition to the new era in which applications have to not only run superquickly and cost-efficiently but also run on a mixture of environments — whether on a business’s own servers or over the public cloud.

With all of the activity happening in this sector called the cloud, VentureBeat has decided to create a “Cloud Technology Index.” The index will track the most compelling companies helping businesses adapt to the cloud.

We designed this curated index to help chief information officers, marketing officers, and other buyers make sense of the hundreds of vendors in this varied landscape. We kick it off today by pointing to an initial list of top cloud technology companies [see the following pages] based on interviews we’ve conducted with experts in the field. These companies are the ones that appear to have the most momentum and are clearly on the right side of the push toward the cloud.

However, this is very much a preliminary list, one meant mainly to provoke feedback. We now want to open the discussion to the wider community. We will publish our final index at our CloudBeat 2013 event in two weeks (Sept 9-Sept. 10 in San Francisco) once we’ve heard from those among you who have really used the products. That’s why we’re making a call of action today. If you’ve used any of these products, or their competitors, please let us know what you think (survey here). Even after we get user input, this will be very much qualitative. But we plan to issue update reports frequently.

At CloudBeat, we’ll be debating the future of the cloud and hearing from most, if not all, of the companies listed below.

The cloud market is huge, but expects say that in some ways it’s only just started. The worldwide public cloud service market is about $131 billion in 2013, according to Gartner, which predicts it will grow by 62 percent to more than $160 billion by 2015. That number comes from all of the cloud apps, services and infrastructure that businesses manage every year. Companies will need help making all of these investments work properly. That’s where the cloud integrator companies come in.

Consider this: Enterprise companies alone will buy $22 billion worth of cloud apps, or so-called Software-as-a-Service apps, by 2015, according to Gartner. That’s up from more than $14.5 billion in 2012. These include popular apps as Salesforce, Workday, and Box. Here again, businesses will need help making sure these apps talk with each other in real time, perform reliably, and cost-effectively.

If you fill out a survey on one or more of the products mentioned in this report, we’ll offer you the results of our expanded report about these companies — for free.

You could also call these cloud technology companies the “middleware companies” of the cloud revolution. You have them in every wave of technology revolution. During the client-server revolution, you had companies like BEA that helped created the first standards-based Java application server — a technology other companies adopted to help them to serve their apps. Oracle acquired BEA for $8.5 billion in 2008. Middleware companies like BEA create massive value during a specific era, but they are often transitionary.

The cloud era may actually have fewer of these so-called middleware companies than we’ve seen in previous periods. That’s because companies seek to be able to use whatever app they want, on top of whatever infrastructure they have. By using APIs, less expensive open-source software, cheap commodity parts, and other free protocols, companies are likely to refuse or avoid paying middlemen large amounts of money for integration.

Indeed, we may see just five breakout integrators this time around, compared to around 10 in previous eras, said Snaplogic CEO Gaurav Dhillon in an interview with VentureBeat. Dhillon knows a thing or two about middleware. He cofounded Informatica, which emerged as a key middleware player in the 1990s when it helped enterprises extract data from their applications. Now he’s leading Snaplogic, which helps integrate cloud apps with other applications.

The cloud era has another difference: Enterprise companies are less likely to want to buy all of their software apps from a single vendor to save costs. They expect to use best-of-breed software, and they expect to glue it all together easily. It is a more “modular” era, as many cloud observers have pointed out. That’s what makes these companies that offer the glue between those modules so significant.

Finally, some very significant companies didn’t make our list in the following pages, including Salesforce, HP, and Rackspace, which are very active in the cloud and can be considered cloud leaders in many respects. We had space for just 10, and we wanted to make sure we included some smaller companies that are showing strong momentum. And there are other reasons we didn’t include these big players. For example, Salesforce’s Heroku platform has very significant traction among developers, and Salesforce is building some very interesting data services for cloud apps. However, the peloton of competitors has caught up in some of these areas. There are now strong alternatives to the Salesforce app platform, especially for developers wanting to develop enterprise grade apps (we’ll mention some below). Another big player, VMware, is also not on the list, but that’s partly because its sister company, Pivotal, did make the list, and we didn’t want to duplicate.

Click through to the following page to see the first company we think is a leader in helping the cloud “grow up.”

Amazon is an unquestioned leader in integration because its public cloud gives businesses a way to run any cloud app they want. Amazon is way out front in the competition in public cloud infrastructure with its AWS service, and it continues to build that lead. This product competes against Microsoft’s Azure, Rackspace, HP, IBM’s Softlayer, and a long list of others.

But Amazon is moving aggressively beyond merely providing cloud infrastructure like computing (EC2) and storage (S3). Amazon is building out other services, including a platform of tools aimed at enabling developers to focus on what they do best and not have to worry about the rest. For example, Amazon has launched a Platform-as-a-Service (PaaS) called Beanstalk, which gives developers version control, collaboration tools, and provisioning.

Sure, all of these services make Amazon’s cloud infrastructure more attractive as a building block for businesses. But Amazon has a long way to go at reassuring enterprises that it can do more than that — for example, it could offer service level agreements (guarantees of reliability) and security standards that companies are used to. Businesses storing and serving their data with Amazon never know exactly where Amazon is keeping this data, and Amazon doesn’t run dedicated servers that ensure company data is separate from data belonging to other companies.

Also some large businesses are eager to shift their investments to open-source cloud infrastructure technologies, including OpenStack or Eucaplytus, which they can customize it themselves in a so-called private cloud. The question is whether and when these competing technologies will get enough adoption to give Amazon a run for its money.

Finally, another big trend challenging Amazon is the one toward the “hybrid” cloud, where many enterprise chief information officers (CIOs) seek to shift their workloads between public and private clouds. Amazon has recently forged an alliance with Eucalyptus, so that companies can bridge their private clouds with Amazon AWS. However, it’s not clear this is a credible offering yet for many CIOs. It’s not clear how well Amazon will coordinate with Eucalpytus, a relatively new company spun out of a university research project. If you’re a conservative CIO at a Fortune 100 company, you’re still more likely to choose a private cloud from an established player like Rackspace, tightly integrated with a Rackspace public cloud, or a public cloud run by VMware tightly integrated with VMware technology running in a data center under your direct control.

If you’ve used Amazon’s cloud products, please let us know what you think, and get our free full report when it is released next month.

Google’s Compute Engine service is just one of a number of competitors to Amazon as a public cloud provider. However, the resources that it brings to this battle are formidable.

Google is already moving quickly to become a serious player. Its relatively new App Engine is coming on strong as a PaaS for developers to build applications on top of. By having these two parts of the stack, Google is now in the camp of big players, free to keep working to attack higher levels of the stack. This gives it a leg up on some other companies like Salesforce, which have been players in the cloud for sometime.

Salesforce, for example, doesn’t offer underlying cloud infrastructure even though it has great traction with PaaS (Salesforce’s Heroku), SaaS (Salesforce.com), and other platforms-as-a-service (Data.com and Database.com). This means Google is well placed to onramp enterprise companies and other developers early on in the lifecycle and then continue to upgrade customers to other of its services as it builds them out.

Last month, Google also started letting developers use PHP on App Engine, a significant move considering that PHP is one of the web’s most popular languages. It means companies will be able to use Google to run their enterprise-scale big data backends (Google is moving forward here with MapReduce, BigTable, and BigQuery) and, yes, consumer web projects, all in the PHP language that is increasingly finding use among corporations.

However, here’s Google’s challenge: It remains an advertising company at its core, not well positioned to sell to enterprise. Google will have to go to considerable lengths to convince enterprise users of its seriousness. Some skeptics see Google’s moves to date more driven by its need to bolster Android as the leading mobile OS and thus to capture mobile developers as early as possible in the cycle.

If you’ve used Google’s cloud products, please let us know what you think, and get our free full report when it is released next month.

Microsoft has moved with impressive speed lately to bolster its credibility in the cloud. Microsoft is unique, its executives claim, in its capability to help customers use the same infrastructure software whether it they are running apps on-premise or in the cloud. Microsoft’s initiatives support hybrid cloud environments, where public and private clouds are tied together.

Microsoft has also signed a deal with Oracle that permits Microsoft to support the running of enterprise-popular Oracle apps, something that other infrastructure providers like VMware can’t do as seamlessly. While VMware can run Oracle on a VMware instance, Microsoft’s deal will allow Windows Azure to management the Oracle more efficiently.

Microsoft’s reach extends beyond the infrastructure layer: It offers its own platform as a service, Windows Azure. Indeed, in another move that will appeal to enterprise companies that are used to Java-based applications, Microsoft and Oracle are also working to bring Java support to Azure.

Microsoft also own SaaS apps that can run anywhere –- either hosted remotely and served from Microsoft servers, or running on top of public or private cloud infrastructures owned or managed by enterprise companies themselves. Office 365 comprises Microsoft’s popular Office suite – Word, Powerpoint, Excel, etc. – and Exchange Server for e-mail, Sharepoint for internal social networking, and Lync for communication and conferencing. Microsoft is also integrating things like Yammer for group collaboration, Skype for calls, and SkyDrive for storage.

In August, Microsoft also announced that it is adding PowerBI, a suite of business intelligence and data mining tools. This makes it easier for employees to do sophisticated analysis, helping companies avoid hiring and training data analysts to use things like Hive or MapReduce.

Microsoft is betting companies will want to buy software and infrastructure from a single vendor. There’s a significant cost to but and integrate software from up multiple vendors, according to Scott Guthrie, the corporate vice president of Microsoft’s developer division. “When things go wrong, who’s throat do you choke?” he told VentureBeat in an interview, referring to the frustrations that many companies have when their systems break down or run unreliably.

According to this argument, enterprise customers can call up Microsoft’s CIO office, and hold it responsible for fixing integration problems. “To have one mission support contract with Microsoft, it can simplify someone’s life, ” says Guthrie.

And if companies want to run popular third-party party apps like Workday, Salesforce, or Google Apps, they can do so on top of Microsoft’s Windows Azure cloud and get things like single sign-on functionality and security and identity management across all of these apps.

As such, Microsoft aims to lead a big trend: The move to a more “modular” stack, where companies simply plug and play public and private cloud app infrastructure as they like — depending on what they deem efficient, cost-effective and convenient.

On the other hand, Microsoft has a track record of being antagonistic to open source software, which is widely popular among IT executives, for being cost effective and offering code-level access. Microsoft’s challenge will be whether it can really continue to offer everything to all people and still satisfy them.

If you’ve used Microsoft’s cloud products, please let us know what you think, and get our free full report when it is released next month.

The move by large businesses to embrace open source is providing momentum for well-heeled newcomer Pivotal.

EMC and VMware, along with GE, created the $1 billion-dollar venture Pivotal this year. The company’s goal is enable people to create enterprise-grade applications that run on the cloud — but with an open-source software driving it all.

Later this year, Pivotal rolls out PivotalOne, its main platform that brings together multiple pieces, including the incorporation of its big data assets. Indeed, CEO Paul Maritz is expected to make news about this at our upcoming CloudBeat event in September.

Pivotal doesn’t intend to play at the infrastructure layer, where its federation partner, VMware, is very much a leader. (VMware is a main backer of Pivotal, but the two companies are run independently). Pivotal wants to abstract that layer so that developers can support any app, regardless of whether it will run on VMware-run clouds, Amazon, or elsewhere.

Pivotal already supports Amazon, and later this year it will run behind firewalls on public clouds, too.

PivotalOne will incorporate several entities. First it will include Cloud Foundry, its open source platform-as-a-service that is already up and running. Cloud Foundry supports JavaSpring, Ruby, Node, Scala, RabbitMQ, and Redis. Second, PivotalOne will have other data and analytics technologies, including big-data tool Hadoop. Pivotal is doing this by drawing on technologies from its Greenplum, Gemfire, Cetas and PivotalHD properties.

Pivotal is still getting off the ground, and its Cloud Foundry PaaS will have to compete with other popular PaaS’s, like Azure and Salesforce’s Heroku, Apprenda, CloudBees, Gigaspaces, and Redhat’s Openshift. However, Pivotal’s strength comes from its open-source roots and capability to wrap in world-class big data and analytical tools, something Salesforce doesn’t have yet. And by abstracting the infrastructure layer, the PaaS should be able to run on any cloud. There it is similar in its ambitions to another other leading PaaS, Engine Yard.

If you’ve used Pivotal’s cloud products, please let us know what you think, and get our free full report when it is released next month.

IBM is a giant in the enterprise, and no one should overlook it. Valued at $202 billion, IBM’s entire business is focused on helping enterprise companies with their technology needs, and so it brings more resources to bear here than any other company on our list, perhaps with the exception of Microsoft. Amazon and Google, while also large companies, still have most of their resources tied up with the consumer products that made them popular.

IBM knows it has to bet big on the cloud. It needs large companies to continue to rely on it as a technology supplier — and that means furnishing companies with technology that works well with other technologies. Of course, that includes making sure it adapts to the cloud revolution.

Already, IBM is acting as an integrator in most areas of the cloud. Much of its cloud tools are housed under its WebSphere brand. IBM acquired Cast Iron Systems, a leader in helping companies integrate their SaaS applications, in 2010. Websphere competes against a bevy of other younger competitors in the SaaS integration area, including MuleSoft, Snaplogic, Rapier, and Cloudwork.

IBM is also big enough that it could potentially acquire or roll up a bunch of other fast-growing companies in related areas. A host of companies, including Puppet Labs, Opscode, SaltStack, CloudVelocity and others are all helping IT executives administer their infrastructures and workloads in useful ways.

Similarly, when enterprise companies seek to integrate sophisticated data services, IBM Information Management is a leader, along with others players like Greenplum, Teradata, and Oracle.

And finally, in July IBM completed the acquisition of a leading cloud computing infrastructure provider Softlayer. That’s a nice complement to IBM’s existing offering of more than 100 SaaS apps, which cover many fields: marketing, procurement, e-commerce, customer service, human resources and city management.

In other words, IBM has quickly emerged as a big player at every level of the stack.

IBM is so big and slow that it is its own worst enemy. Developers perceive it as serving mostly legacy enterprise customers. But those enterprise customers still have the biggest budgets, and IBM continues to ride with them into the cloud. These are the “guys I lose the most sleep about,” says Leo Spiegel, the SVP of strategy and corporate development at Pivotal, referring to IBM.

If you’ve used IBM’s cloud products, please let us know what you think, and get our free full report when it is released next month.

Righscale has emerged as a leader when it comes to helping companies manage multicloud environments. It helps businesses run apps on whatever infrastructure they might have, whether they are public, private, or hybrid clouds. Rightscale supports eight public clouds, including Amazon AWS, Rackspace, Windows Azure, Google Compute Engine, HP, SoftLayer, IDCF, and Datapipe as well as private cloud providers OpenStack and CloudStack. Its customers include the Associated Press, CBS Interactive, Intercontinental Hotels Group, PBS, and Zynga.

Zynga is a good example of a Rightscale customer. The mobile and social game company built one of the earliest versions of a hybrid cloud, mixing Amazon with its own private cloud to create something it called Zcloud. Zynga managed it using Rightscale. The company said it was able to get rid of two out of every three servers.

Rightscale has raised more than $58 million in funding. Chief executive Michael Crandell says its revenue and valuation has continued to increase recently. The company is well placed to ride the push toward a hybrid cloud now that Dell acquired one of its main competitors, EnStratus. Dell has struggled to find focus now thanks to its struggling core PC business, and the protracted battle over who actually owns the company is likely to slow investment in EnStratus.

Rightscale also competes against players like VMware, which has a suite of tools to manage infrastructure. However, VMware is far more focused on managing virtual machines (VMs) inside the enterprise data center, and less interested in doing this inside an Amazon cloud, which has become more commoditized as Amazon itself has added more features for this. VMware will also release its hybrid cloud offering out of beta in the next month or two, which will provide Rightscale with more competition. However, VMware intends mainly to strengthen the link between on-premise and off-premise instances of VMware, which touches only a portion of Rightscale’s business.

While Rightscale has emerged as a leading manager of underlying cloud infrastructures, MuleSoft is a leading player in a second category of companies: Those helping apps talk with other apps. MuleSoft helps companies integreate SaaS apps so that they work well together, whether they run hosted offsite or behind the firewall.

MuleSoft calls its service an integration-platform-as-a-service (iPaaS) and branded its product CloudHub.

CloudHub enables companies do things like run Salesforce.com, Intuit, Authorize.net, Amazon, Twitter, and Facebook together, making sure that changes in one app are reflected in all of the other applications as they happen in real time. CloudHub boasts more than 120 prebuilt connectors for apps, which also include Amazon S3, Gmail, Hadoop HDFS, Magento, PayPal, and Twilio.

MuleSoft CEO Greg Schott says businesses spend about $500 billion dollars every year doing customized work on point-to-point app integrations to make them work to meet IT security, compliance, and performance needs. And apps connections are exploding, as mobile and SaaS apps take hold and public APIs begin to hit the thousands.

MuleSoft competes against the likes of Tibco, a much bigger player that so far has focused mainly on application integration for the enterprise. However, Tibco has recently been building out its cloud offering, including announcing Tibco Cloud Bus last month. MuleSoft also competes against a host of other players focused more on the cloud, including Zapier, Cloudwork, Dell Boomi, and Snaplogic.

Schott doesn’t provide specific guidance on the company’s revenue momentum, but he told VentureBeat the company’s revenue will double this year after more than doubling last year.

MuleSoft also has an interesting business model. It bills up to eight-figure contracts for enterprise companies for help on complex app integration. In other cases, MuleSoft helps integrate a single SaaS app for an enterprise customer and charges based on a percentage markup on the overall contract value. This might be sold at 15 cents on the contract’s dollar value. For example, if a SaaS contract runs for $100,000 a year, a customer may end up paying $115,000 to include integration from MuleSoft, with the $15,000 being kicked back to MuleSoft.

The company has raised $37 million from NEA and Salesforce.

If you’ve used MuleSoft’s product, please let us know what you think, and get our free full report when it is released next month.

New Relic represents yet a third category of companies helping drive the move toward the cloud: those offering tools for developers to help companies manage their environments and that run across apps.

New Relic, for example, offers a sort of aircraft control system for apps running on on a company’s stack. It enables a company to peer into the performance of apps, including data and metrics indicating whether they are running securely and robustly.

New Relic competes against AppDynamics, another company seeing very strong growth. Until now, AppDynamics has targeted midsized to large companies that often run their apps on-premise and behind a firewall. New Relic has so far focused on its SaaS offering — finding more resonance among smaller or midsized companies.

But New Relic is clearly moving up-market. It has increased customer accounts by more than 10,000 in the most recent quarter, bringing the total 50,000. It is also benefiting from the release of its API, so that third-party companies can build app plugins to perform their own data analysis within apps.

If you’ve used New Relic, please let us know what you think, and get our free full report when it is released next month.

With the proliferation of mobile devices and apps we’re all using, how do businesses secure their data and manage who can or can’t access various apps and data and set policies for such usage? Centrify has emerged as one of the more interesting businesses helping companies to do this across all of their environments: on-premise data center, mobile devices, and cloud apps.

Companies no longer just manage identities and access privileges across on-premise systems such as Windows and Linux. They also have to manage apps on mobile platforms as well as SaaS apps hosted onsite — or even offsite. Centrify enables companies to use their active directory domain to manage users and devices through one software. For example, it ties the single sign-on (SSO) protocols of cloud apps to the active directory. Even if apps don’t support a protocol, Centrify can simplify access by enabling end users to store their login info in a cloud-based Centrify vault.

Founded in 2004, Centrify has raised $52 million from investors and says it’s growing at 40 percent annually, with revenue of $50 million this year. It competes against others like Okta and Ping Identity, both of which have raised significant cash. Last month, Ping raised another round, making for a total of $78 million. However, Centrify is positioning itself as the only company that can support both the data center and the cloud, with Okta and Ping focusing mainly on the cloud and bigger legacy players like Computer Associates, Oracle, and Dell focused on the data center. It also scored a victory in signing a deal this year with Samsung, which is using Centrify in its Knox security service.

The question is how big Centrify can become, given that the overall market for identity management is only about $4 billion. The cloud-identity management segment was worth $200 million in 2012, according to Gartner, which expects the market to grow to $800 million by 2016 at a 41 percent annual rate. Will Centrify be able to locate derivative services that will help it grow?

If you’ve used Centrify, please let us know what you think, and get our free full report when it is released next month.

Like New Relic, Sumo Logic is another company offering an important DevOps tool needed by businesses to help manage and operate what they are doing with their cloud environments.

Sumo Logic provides analysis of log data across a business’s apps, severs, network and other IT infrastructure, and regardless of whether it runs on Amazon AWS, a private cloud, or comes from a customer app, or a mobile phone: “As long as it has a time stamp on it, it doesn’t matter to us,” said Sanjay Sarathy, the company’s head of marketing.

Sumo Logic helps administrators tracks that log data in real time, and helps them get digestible and actionable information about their whole environment, from Cisco network switch logs on up the stack.

The company’s LogReduce sorting system uses machine learning to filter log file data into patterns. That way, it can find sources of problems you may not even know to look for. For example, if you’re an IT manager and see some errors in a java application running across your system, it might take you hours to find the source of the problem. You might have to wade through 50,000 log messages from just a two-minute period. Sumo Logic, by contrast, can look through messages it sees across your infrastructure, instantly, including those coming from the Apache application server and the Linux OS it runs on top of. It might find the problem is not actually from the Java application, but from a faulty process in a linux server that affects the app.

The heritage of its founders has won it credibility within enterprise circles. Co-founders Kumar Saurabh and Christian Beedgen previously both held key positions at log management and security company Arcsight. Founded in 2010, Sumo Logic’s director of security was one of the first five employees.

Sumo Logic is the youngest company on this list, and it’s very early in developing its roadmap. It competes against companies like Splunk, Loggly, and VMware. IBM has also recently come out with a beta product in this area. Sumo says its advantage is in the speed of its analytics.

Sumo Logic has now raised $50.5M from investors.

It hasn’t released data on revenue, but the company’s first quarter brought in more revenue than the full previous year combined, according to Sumo Logic’s Sarathy. The company has 130 customers, including Netflix, Tableau, McGraw Hill and GoGo Inflight.

The company’s immediate targetable market is about $8-10 billion, but as machine-to-machine communications grow over time, the market could eventually double or triple, said Sarathy.

If you’ve used Sumo Logic, please let us know what you think, and get our free full report when it is released next month.